A nasal interface device (10) delivers a high flow rate of a gas having a pressure that is adjustable to a patient. The device includes a nasal insert (100) that is adapted to deliver pressurized breathing gas to a nasal cavity of the patient, and to receive expired air. The nasal insert has a pressurized breathing gas delivery port (116) and an expired gas port. The expired gas port has a plurality of openings extending therethrough.
